Heat exchangers



April 11, 1961 R. A. NICHOLSON HEAT EXCHANGERS Filed Oct. 8, 1956 INVENTQR- ATTORNEY Un d S at s at n HEAT EXCHANGERS Ralph A. Nicholson, Brady, Tex., assignor to Intercon tinental Manufacturing Company, Inc., Garland, Ten, a corporation of Texas Filed Oct. 8, 1956, 'Ser. No. 614,422

2 Claims. (Cl. 257-247) This invention relates to heat enchangers and more particularly to a heat exchanger for cooling fluids.

An object of the invention is to provide a new and improved heat exchanger.

Another object is to provide a heat exchanger having a refrigerant passage through which a refrigerant fluid may be circulated and a fluid passage disposed adjacent the refrigerant passage through 'which a fluid to be cooled may be circulated.

Still another object of the invention is to provide a heat exchanger, of the type described above, wherein the fluid passage is considerably longer than the refrigerant passage. p

A further object of the invention is to provide a heat exchanger of the type described above, wherein the fluid passage extends on both sides of the refrigerant passage. I

Another object is to provide a heat exchanger having a flat body of heat conductive material provided with a middle tortuous or sinuous refrigerant passage and a pair of fluid passages which are disposed on opposite sides of the refrigerant passage.

Still another object is to provide a heat exchanger, of the type described above, wherein the fluid passages are connected at one pair of adjacent ends whereby fluid to be cooled may be circulated through one fluid passage on one side of the refrigerant passage and then through the other fluid passage on the other side of the refrigerant passage. 7

A further object is to provide a heat exchanger formed of four juxtaposed plates joined together influid tight relationship, the two inner plates having corresponding corrugations or convolutions which form a tortuous or sinuous refrigerant passage, the two outer plates having similar corrugations or convolutions which forma pair of fluid passages immediately adjacent the refrigerant passage and on-opposite sides thereof. v

A still further object is to provide a heat exchanger, of the type described above, wherein anadjacentpair' of ends of the fluid passages are in communication with one another through a pair of aligned apertures provided in the two inner plates. r 1

Another objectris to providea heat exchanger, of the type described above, wherein the other pair of ends of the fluid passages are provided with suitable inlet and outlets means whereby fluid to be-cooled may flow through the inlet "meanswo one of the fluid-passages, through such passage andthe aligned apertures in the inner plates to theotheffluid passage'and thence to the outlet means.

For a better understanding "of the invention, reference may ybe-hadt6 the following description takenin coniiction with uie sccanp'snyin drawing and its scope will be pointed out in the appended claims.

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Figure 1 is a side view of sheet exchangers (instructed in accordance with the invention and with portions thereof broken away;

Figure 2 is a sectional view taken on line 2--2 of.

Figure 1;

Figure 3 is an enlarged sectional view taken across the refrigerant passage and fluid passages of the heat exchanger, the dimensions of the fluid passages being exaggerated; and,

Figure 4 is an enlarged sectional view taken on line 4-4 of Figure 1.

Referring now to the drawing, the heat exchanger 19 comprises juxtaposed or superposed inner plates 11 and 12 and outer plates 13 and 14 which are preferably, but not necessarily, rectangular in shape. The inner plates 11 and 12 are embossed, stamped or processed in anyiother suitable manner to provide corresponding convolutions or' corrugations 15 and 16, respectively, which form a tortuous or sinuous refrigerant passage. 17. An inlet fitting 18 is rigidly secured to the inner plates to communicate with the inlet end of the refrigerant passage while an outlet fitting 19 is similarly rigidly secured to the inner plates to communicate with the outlet end of the refrigerant passage.

It will be apparent that refrigerant fluid, such as Freon gas from a suitable refrigerationapparatus, not shown, may be admitted into one end of the refrigerant passage 17 and flow therethrough in the tortuous or sinuous path, defined by the convolutions or corrugations 15 and forming the refrigerant passage 17, to the other end of the refrigerant passage and back to the refrigeration unit through the outlet fitting 19. It will be apparcut that the inlet and outlet fitting have threadedouter porions 20 by means of which suitable conduits of the refrigeration apparatus may be connected thereto.

The refrigerant fluid, of course, is cold and absorbs heat from the inner plates to cool them. The refrigerant fluid may be Freon gas which is allowed to evaporate from a liquid state to a gaseous state in the refrigerant passage whereby it absorbs the heat required to evaporate tt'from the inner plates.

The outer plates 13 and 14 are also embossed, stamped or processed in any other suitable manner, to form convolutions or corrugations 25 and 26, respectively. The corrugations 25 of the outer plate 13 are aligned with the corrugations 15 of the inner plate 13 but are spaced therefrom to form an arcuate passage 27, between the inner platell and the outer plate 13, which follows or is aligned with the refrigerant passage 17 and is disposed on one side thereof fror'n'the inlet fitting 18 to the outlet fitting 19'ther'eof. The corrugation 25 has a horizontal'extension 2-8 which provides an inlet exten sion passage'29 which extends between and communi cates with one end of the passage 27 and with the bore I of the inlet fitting 3i! which is' secured to th'eflheat' exchanger plates 13 and 1 1. f.

The corrugations" 26 of the'outer plate 14- is disposed on the side thereof opposite from the passage tendsbetween'and. communicates withone end of the passage 3 2andwith the bore of the outlet fitting 36 which is secured to the'heat exchanger plates 14 andi12; 5 The 'inner plates 11 and12 adjacent the'extens'ionsf 28 and 34 may be cut away or slotted to receive the inner I 4 ends of the fittings 30 and '36, the outer plate 13 having corrugations 37 and. 38 which. abut theinner portions ofq,

the fittings 30 and 36,: respectively, and the outer plate 14 having corrugations and 40' which abut the inner if, portions of the fittings 30 and 36. The portion of the Patented Apr. 11, 1961 are aligned: with the corrugations 16 of the inner plate 12 but are spaced therefrom to form an arcuate passage 32,"between the inner plate and the outer plate 14, which fol lows or is aligned with the refrigerant passage 17 and v inlet fitting 30 adjacent the inner plate 12 and the outer plate 14 is closed, as at 40, so that the bore of the inlet fitting 30 does not communicate with the outlet extension passage 35 and the portion ofthe outlet fitting 36 is closed, as at 41, so that the bore of the outlet fitting 36 does not communicate with the inlet extension passage 29.

The corrugations 25 and 26 of the outer plates 13 and 14 have terminal extensions 44 and 45 adjacent the outlet fitting 19 which are aligned with each other and with apertures 46 in the inner plates 11 and 12 whereby the ends of the arcuate passages 27 and 32 remote from the inlet and outlet fittings 30 and 36 communicate with each other. Thus it will be apparent that fluid to be cooled is introduced into the heat exchanger through the inlet fitting 30 into the inlet extension passage 29 between the inner and outer plates 11 and 13, thence to one end of the arcuate passage 27 between the plates 11 and 13, through the arcuate passage 27 to the terminal extension thereof provided by the terminal extension 44 of the corrugation 25, through the aligned apertures 46 of the inner plates 11 and 12 to the terminal extension of the arcuate passage 32 provided by the terminal extension 45 of the corrugation 26, thence to the end of the arcuate passage 32 remote from the outlet fitting 36, and then through the arcuate passage 32 to the outlet fitting 36 and from there, by suitable conduit means, to a point of use.

The inner and outer plates are rigidly secured together by welding both to cause the various passages to be fluid tight or sealed and to obtain good heat transfer characteristics between the plates. The welding may be done in any suitable manner, such as spot welding between the corrugations where the plates have flat portions which abut one another. The various fittings may also be welded in place.

In use, the heat exchanger 10 may be immersed in a eutectic or disposed in a heat insulating medium, as desired. In some cases immersion in a eutectic is preferred so that the eutectic may be frozen by the refrigerant fluid during periods of slow or no movement of the liquid to be cooled through the heat exchanger and may melt to absorb heat from the liquid to be cooled during periods of intense or rapid movement of liquid through the heat exchanger. Disposition of the heat exchanger in a heat insulating medium prevents extra'neous heat from flowing to the heat exchanger. Refrigerant fluid is then circulated through the refrigerant passage 17 from the inlet fitting 18 to the outlet fitting 19. The liquid to be cooled is circulated from the inlet fitting 30 to the outlet fitting 36 first on one side of the refrigerant passage .17 through the arcuate fluid passage 27 and in the same direction as the movement of the refrigerant fluid in the refrigerant passage and then on the other side of the refrigerant passage 17 through the arcuate fluid passage 32 but in a direction opposite to the movement of the refrigerant fluid in the passage 17, the liquid to be cooled reversing its direction of flow upon passing through the registering or aligned apertures 46 of the inner plates. The arcuate passages 27 and 32 are quite narrow so that the liquid to be cooled flows in very thin arcuate sheets in intimate contact over a very large surface area with the corrugations and 16 of the inner plates which form the refrigerant passage. As a result, a very quick and eflicient transfer of heat takes place from the liquid to be cooled to the refrigerant fluid.

It will now be seen that a new and improved heat exchanger it} has been illustrated and described which in- 4 which a refrigerating fluid may be circulated and with a pair of fluid passages, of arcuate cross-sectional shape, disposed on opposite sides of" the refrigerant middle passage and having one pair of adjacent ends in communication with each other whereby the liquid to be cooled may be circulated in one direction through one fluid passage on one side of the refrigerant passage and then in the opposite direction through the other fluid passage, the liquid to be cooled being admitted at an end of one fluid passage remote from adjacent pair of ends andbeing extracted from the end of the other fluidpassage also remote the adjacent pair of ends.

It will also be seen that a heat exchanger having the required arrangement of, refrigerant and fiuid passages has been illustrated and described which is easily and economically constructed of four plates having convolutions or corrugations which form the passages.

It will also be seen that an efficient and effective heat conduction or transfer relationship between the plates is obtained by welding the plates to each other.

It will be apparent that various changes in the, construction of the heat exchanger can be made without departing from the invention and it is intended, therefore, to cover in the appended claimsv all such changes or modifications as fall within the true spirit and scope of the invention.

What I claim is new and desire to secure by Letters Patent of the United States is:

1. A heat exchanger comprising a pair of abutting inner flat plates having opposite outer sides and having corresponding outwardly displaced portions forming a refrigerant passage having inlet means and outlet means at opposite ends, and a pair of outer flat plates, said outer plates abutting opposite outer sides of the inner plates, said outer plates having outwardly displaced portions forming with the outwardly displaced portions of the inner plates fluid passages on opposite sides of said refrigerant passage, said inner plates having registering apertures affording communication with one pair of adjacent ends of said fluid passages, the other ends of said fluid passages being provided with inlet and outlet means, respectively.

2. A heat exchanger comprising a pair of abutting inner flat plates having opposite outer sides and having corresponding outwardly displaced portions forming a refrigerant passage having inlet means and outlet means at opposite ends, and a pair of outer flat plates, said outer plates abutting opposite outer sides of the inner plates, said outer plates having. outwardly displaced poriiODS forming with the outwardly displaced portions of the inner plates fluid passages on opposite sides of said refrigerant passage, said inner plates having registering apertures affording, communication. with one pair 'of adjacent ends of said fluid passages; opposite ends of said fluid passages being provided with inlet and outlet means,

respectively, said plates being rigidly secured together in eflicient heat transfer relationship to one another.

References Cited in the file of this patent UNITED STATES PATENTS Germany Apr. 25, 

